Published German Patent Application No. 32 02 614 is representative of prior art relating to closed-loop control systems with error correction that form the background for the present invention. This patent discloses a device for regulating fuel injection when starting a self-igniting internal combustion engine. The regulating device has a PI-controller (proportional/integral controller) with an upstream counter. The PI-controller is connected to a sensor that detects the crankshaft position of the internal combustion engine.
The PI-controller receives a setpoint value derived from a characteristics field. The characteristics field is derived from operating parameters of the internal combustion engine. A second characteristics field, called a control characteristics field, also is provided. The output value of the second characteristics field is added to the output value of the PI-controller. If any error is detected, the output value of the PI-controller is disabled. An error condition exists, for example, when the sensor, the counter, or other components of the regulating device does not operate properly.